Periodontal disease, which includes any abnormality, whether inflammatory or degenerative, of tissue around a tooth, is very common worldwide. For example, the World Health Organization has estimated that even if there were no new periodontal disease, it would take 45 years to treat those people who are affected. In addition, the Journal of Public Health Dentistry concluded in 1985 that "more than two out of three patients were affected by periodontal disease." Moos, W.F., Medical Marketing & Media, 52-54 (1985). Chronic gingivitis (i.e., inflammation of the gingiva or gums) and chronic destructive periodontitis (i.e., a disease of the connective tissue which attaches a tooth to the alveolar bone, which results in alveolar bone resorption, increasing mobility of the tooth and, ultimately, tooth loss) are two common types of periodontal disease.
Although chronic periodontal disease is so common and known to be caused ultimately by bacteria accumulated on the teeth and under the gingiva, progress in its prevention and treatment has been limited and therapy is still largely unsuccessful. Preventive techniques rely heavily on establishing and maintaining good oral hygiene and therapy of existing periodontal disease includes expensive and ongoing treatments, such as periodontal surgery, which, in many cases, must be carried out often and has not been clearly shown to be effective in arresting alveolar bone loss and preserving teeth. Alveolar bone loss or resorption, which occurs after tooth extraction, is also a serious dental problem which cannot, to date, be successfully treated. A more effective method of preventing or treating alveolar bone loss would be of great value, particularly because of the prevalence of its occurrence.